Chapter 2: Water Flashcards
What is a polar molecule?
Consists of a positive and negative charge.
is water polar or non polar?
polar
water forms what kind of bonds, weak or strong, covalent or non covalent, and why
-hydrogen bonds
-weak
-noncovalent
-Because the hydrogen of one water molecule with its slightly positive charge can bond to another water molecule’s oxygen with a slightly negative charge
Oxygen and hydrogen, which is positive and neg
Oxygen is more neg
Hydrogen is more pos
difference between covalent and non covalent bonds
-covalent bonds share pair of electrons equally, strongest type of bond
noncovalent bonds have 3 types: ionic being the strongest of the 3, takes a bond away
hydrogen, second is when polar covalent bonds are attracted to each other, the last on van Der Waals is the weakest is the asymmetric distribution of electrons
brownian motion?
the movement of molecules powered by random fluctuations of environmental energy
weak bond
brownian motion?
the movement of molecules powered by random fluctuations of environmental energy
weak bond
hydrophilic means?
polar molecules and ionic compounds dissolve in water
hydrophobic means
nonpolar substances are soluble in non polar solvents
‘like dissolves like”
electrostatic interactions is also known as
ionic bonds or salt bridges
acceptors usually
don’t have hydrogen in them, nitrogen or oxygen
donors usually
include hydrogen
hydrogen bonds form between an
electronegative atom and hydrogen
van der Waals
asymmetric, repulsion
hydrophilic substances dissolve in what
water
the hydrophobic effect?
exclusion of non polar groups to maximize the entropy of water molecules, causes protein effect
what happens when a non polar is added to water
water cages the solute making the non polar aggregate
amphiphiles come from phospholipids
hydrophilic head and hydrophobic tail to form cell membrane two types micelle and bilayer, fatty acid
water moves by? solutes move by?
osmosis-is the net movement of solvent across the membrane from a region of high concentration (here, pure water) to a region of relatively low concentration
diffusion
what is an acid/base
acid donates a proton decreases pH
base accepts a proton increases pH
pH meaning?
the acidity of a solution
ph=-log[H+]
ph=7 neutral
>7 basic
<7 acidic
higher pKa?
stronger acid
if a solution contains both acid and conjugate base it is what
a buffer, buffers reisst pH change
determine pH using pH=pKa+log[base/acid]
